From: Valentin Schneider <valentin.schneider@arm.com>
To: Frederic Weisbecker <frederic@kernel.org>
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>, Mike Galbraith <efault@gmx.de>
Subject: Re: [PATCH] sched: Tweak default dynamic preempt mode selection
Date: Wed, 10 Nov 2021 00:03:56 +0000 [thread overview]
Message-ID: <87k0hgswpf.mognet@arm.com> (raw)
In-Reply-To: <20211109102502.GA288354@lothringen>
On 09/11/21 11:25, Frederic Weisbecker wrote:
> On Fri, Nov 05, 2021 at 10:40:35AM +0000, Valentin Schneider wrote:
>> @@ -75,17 +86,6 @@ config PREEMPT_RT
>>
>> endchoice
>>
>> -config PREEMPT_NONE
>> - bool
>> -
>> -config PREEMPT_VOLUNTARY
>> - bool
>> -
>> -config PREEMPT
>> - bool
>> - select PREEMPTION
>> - select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
>> -
>> config PREEMPT_COUNT
>> bool
>
> This must be breaking cond_resched() and might_resched() definitions.
>
> Since CONFIG_PREEMPT_NONE, CONFIG_PREEMPT_VOLUNTARY and CONFIG_PREEMPT aren't too widely
> spread around within ifdefferies, you can:
>
> 1) Rename CONFIG_PREEMPT_NONE to CONFIG_PREEMPT_NONE_STATIC
> Rename CONFIG_PREEMPT_VOLUNTARY to CONFIG_PREEMPT_VOLUNTARY_STATIC
> Rename CONFIG_PREEMPT to CONFIG_PREEMPT_STATIC
>
> 2) Keep the old CONFIG_PREEMPT_NONE, CONFIG_PREEMPT_VOLUNTARY,
> CONFIG_PREEMPT around for compatibility and make them select their
> corresponding BEHAVIOUR entries.
>
Damn, I was too zealous on my inbox clearing and skipped that one, sorry!
(and ofc in the meantime Mike and I went down separate rabbit holes).
The old CONFIG_PREEMPT* would have to remain somewhere in the menu entry
(e.g. "legacy" preemption mode selection?), but other than that it seems to
work with this kind of structure:
choice
prompt "Preemption Model"
default PREEMPT_BEHAVIOUR if PREEMPT
default PREEMPT_VOLUNTARY_BEHAVIOUR if PREEMPT_VOLUNTARY
default PREEMPT_NONE_BEHAVIOUR
This however doesn't solve Mike's concern wrt deselecting PREEMPT_RT to
flip PREEMPT_DYNAMIC and vice versa...
> Thanks.
>
next prev parent reply other threads:[~2021-11-10 0:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-05 10:40 [PATCH] sched: Tweak default dynamic preempt mode selection Valentin Schneider
2021-11-06 4:40 ` Mike Galbraith
2021-11-08 11:17 ` Valentin Schneider
2021-11-08 12:27 ` Mike Galbraith
2021-11-08 15:21 ` Valentin Schneider
2021-11-09 5:30 ` Mike Galbraith
2021-11-09 9:52 ` Valentin Schneider
2021-11-09 11:00 ` Mike Galbraith
2021-11-09 12:19 ` Valentin Schneider
2021-11-09 13:31 ` Mike Galbraith
2021-11-06 5:05 ` kernel test robot
2021-11-08 12:00 ` Valentin Schneider
2021-11-06 5:33 ` kernel test robot
2021-11-06 7:58 ` kernel test robot
2021-11-09 10:25 ` Frederic Weisbecker
2021-11-10 0:03 ` Valentin Schneider [this message]
2021-11-10 5:44 ` Mike Galbraith
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